This invention relates to a spray method for spraying and applying a powdery mold coating agent onto both inside surfaces of a movable metal mold and a stationary metal mold for a permanent mold casting device.
Application of the mold coating agent onto both inside surfaces of a movable metal mold and a stationary metal mold for a permanent mold casting device has previously been carried out as follows. The metal molds have been removed from the device before commencing casting work, and then the mold coating agent has been applied onto both inside surfaces of the metal molds by hand spraying. In the event the mold coating agent has dropped away from the inside surfaces of the metal molds or has been exhausted in the middle of casting work, the mold coating agent has been applied onto this portion by means of hand spray.
In the foregoing application method, however, there have been the following problems. The application work has been done on the basis of experiences and perceptions of workers, so that there have been variations in the amounts of coating applied by the respective workers. Therefore, respective qualities of castings have also been varied. Further, since there have been variations in the thicknesses of the applied and formed mold coating agent films or the service lives of the films, the production has been carried on in a state of "How many times does the mold coating agent film withstand the casting work?" i.e., the service life of the mold coating agent film has not been known exactly, so that there has been a possibility of producing a large number of defective pieces. Moreover, it has been necessary to check the mold coating agent film without interruption during the work, so that its workability has been bad. Furthermore, it has been required for the worker to become skilled to a high degree, however, lack of manpower has become serious problem with the advancing age of workers. In addition, the work environment has become worse due to the mold coating agent being dispersed around the work area.
This invention is made in order to solve the above problems, and an object of this invention is to provide a spray method of permanent mold casting powdery mold coating agent which can improve the workability of application of the mold coating agent, enables the casting work to be automated, and can produce uniform and high quality castings